This invention relates to a method of, and a system for, controlling a proximity transaction using short-range communications devices.
Hand-held portable and mobile devices (such as mobile phones, personal digital assistants (PDAs) and lap top computers) are often provided with a short-range high-speed wireless network interface. One such interface is the Bluetooth interface which is a short-range wireless technology which operates around 2.45 Ghz. Another known short-range wireless technology is the wireless networking technology IEEE802.11b.
When using such a device to undertake a transaction with some other device in close proximity, it is frequently the case that the range of a wireless transmission from the device is such that other devices apart from the one intended to receive the transmission, may pick up the transmission and incorrectly act upon it. For example, a user may wish to instruct a specific printer to carry out a print job using the short-range wireless network interface of a PDA. In such a case, the range of the wireless network interface may be such that printers other than that which is required to do the print job, for example another printer in the same office or down the corridor, may also receive the print request transmission, in which case the user must carry out a further printer identification step, and this may be difficult where there are several such printers.
Known ways of overcoming this problem are to use a directional infra-red link, or to use a menu system on the PDA (or other mobile device) used to send the print instructions. In the former case, the use of a directional infra-red beam makes identifying a particular receiving device less ambiguous; and, in the latter case, the menu system can correctly identify a designated receiving device from a list of possible receiving devices. Both of these solutions do, however, have the disadvantage that a conscious user effort is required, either by specifically pointing a mobile device at the required receiving device, or the navigation of a user interface and the choosing from one or more lists of options.